Joii’s innovation, which is registered as a Class I medical device in the UK, is bringing data to an area of women’s health that has long been ignored and minimised. 

The numbers tell a sobering story. One in three people with periods experience heavy menstrual bleeding. Yet diagnosis can take years. Nearly half of endometriosis sufferers visit their GP 10 or more times before being diagnosed, with 78% reporting they were told they were making a "fuss about nothing”. Many women with adenomyosis, fibroids, PCOS, and other menstrual health conditions describe feeling dismissed or not taken seriously when seeking help.

Using sophisticated AI technology paired with Joii’s specially designed pads, Joii’s Period Evaluation app instantly measures blood volume and clot size with clinical precision. Users simply scan their pad with their phone, eliminating guesswork and providing hard data that cannot be dismissed. 

"We already count our steps, monitor our sleep, and track our heart rate," says Justyna Strzeszynska, Founder of Joii, who developed the app after her own painful journey to a fibroids diagnosis left her anaemic and struggling. "Measuring blood loss is simply the next step to better understanding our bodies and demanding the care we deserve. We want every woman to have proof, not just pain."

Doctors use specific criteria, such as 80ml of blood loss per cycle or clot sizes of over 2.5cm, to assess if someone may have a menstrual health problem, but, until now, patients have had no way to measure these metrics accurately. Joii bridges that gap.

Using the app to measure period volume provides users with objective data rather than relying on subjective terms like ‘heavy’, ‘light’ or ‘normal’ flow or counting how many pads or tampons they use. People can also use the app to track their other menstrual symptoms and their severity, including pelvic pain, pain during sex or clotting, alongside systemic issues such as brain fog, fatigue, cravings, and more. 

These symptom patterns are often associated with conditions like endometriosis and fibroids, yet are frequently underreported or dismissed in clinical settings. Joii helps users record these details clearly, supporting more informed conversations with healthcare professionals.

The app also provides cycle tracking and predictions, doctor visit notes so users can remember what to ask at appointments, educational content and personalised health insights and reports.

How it works

• Buy the Joii Evaluation Pads. They are made of organic cotton and biodegradable polymer and do not contain plastics or perfumes.
• Download the free Joii Period Evaluation app from the Apple App Store or Google Play Store. 
• Scan your pad after use. The app instantly shows flow volume and clot size data.
• Use the insights to track your cycle, spot red flags and share data with your doctor if needed.

A five-month feasibility study conducted with the University of Bradford and funded by Innovate UK, demonstrated the app’s real-world value: 

• 88% of users said it would improve how they communicate period volume with their GP. 
• 52% reported improved period health literacy after using the app. 

Additionally, a separate clinical study found 93% of GPs agreed that the app can support diagnosis of heavy bleeding, and 80% would use it to support treatment planning and monitoring for heavy periods.

The Joii app is free to download (iOS and Android), and the evaluation pads are available in the UK via the Joii online store.

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